High altitude sounding projectile



March 7, 1961 Filed Feb. 11, 1959 WITNESS:

Im. $72K Y- SEKELLA HAL 6? BY 7' MM HIGH ALTITUDE SOUNDING PROJECTILE 2 Sheets-Sheet 1 INVENTORS Mfr/Li A ORZVEY 2 Sheets-Sheet 2 Mien/ZS BY $115 963? 80% ORNEY Y. SEKELLA EI'AL HIGH ALTITUDE SOUNDING PROJECTILE arch 7, 1961 Filed Feb. 11, 1959 i it 2,973,712 HIGH ALTITUDE SOUNDING PROJECTILE Youston Sekella and James J. Digby, Elmira, and Robert J. Covert, Montour Falls, N.Y., assignors to The Bendix Corporation, a corporation of Delaware Filed Feb. 11, 1959, Ser. No. 792,566 6 Claims. (Cl. 102-63) The present invention relates to a high altitude sounding projectile and more particularly to a rocket of the type which is arranged to eject, at the top of its trajectory, a floating reflecting screen or target suitable for tracking by radar or the like.

Projectiles of this type which have been found useful in plotting the air currents in theupper atmosphere commonly comprise a dart-shaped hollow body containing a plurality of spools of metallic ribbon with means for ejecting the spools at the top of the trajectory of the projectile in such manner as to form a jumble or cloud of chaff of sufficient volume and continuity to form a radar reflector or target. Ejection of the chaff has heretofore been accomplished by means actuated by an explosive charge the detonation of which is controlled by various timing arrangements.

In devices of this type it has been found difficult to secure reliably the complete unwinding of the spools of chaff together with the intermingling and continuity of the strands desirable for producing a good radar target. Even when the ejection charge is reduced to the minimum required to function, the chaff is liable to be broken up and dispersed to such an extent as to render it difiicult to track. Difiiculty has also been experienced due to the matting together and adhesion of the packages of chaff caused by the explosive ejection forces.

It is an object of the present invention to provide a novel meteorological projectile which reliably furnishes a well-spread but not too widely dispersed mass of chaff forming an excellent radar target.

It is another object to provide such a device in which the ejection of the chaif is triggered by a timed explosive charge, but the ejection itself is accomplished by means of a spring-actuated device.

It is another object to provide such a device in which the spools or packages of chaff in the projectile are protected from contact with the explosive charge.

It is another object to provide such a device which includes means for preventing the spools or packages of chaff from matting together or telescoping due to the force of ejection.

It is another object to provide such a device in which the spools or packages of chafi are separated from each other, and protected from compression by the ejecting means. i

It is another object to provide such a device in which ribbons of chaff are caused to trail the projectile by a common attachment until completely unwound and are then out free from the projectile while maintaining a ter minal attachment with each other.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation, partly broken away and in section, of a preferred embodiment of the invention;

Fig. 2 is an exploded view on a reduced scale of portions of the body and tail sections of the projectile with the spools of chaff and the ejecting means therefor;

Fig. 3 is a section taken'substantially on the line 3-3 of Fig. l; and

Fig. 4 is a view similar to Fig. l of a portion of the body section of a second embodiment of the invention in which the chaff is in the form of packages of short pieces of the material.

2,973,712 Patented Mar. 7, 1961 In Fig. 1 of the drawing there is illustrated a dartshaped projectile having a nose section 1, a tubular body section generally indicated by the numeral 2, into which the nose section 1 is threaded, and a tail section 3 having a reduced extension 4 telescopically fitted within the adjacent body section 2 to form a closure therefor, and retained therein by a plurality of frangible pins 5.

A tubular casing 6 is located in the body section 2, being held in concentric spaced relation thereto at the front end by means of a capsule holder and anchor member 7 fixedly mounted in said body section by means of the screws 8, and having a portion 9 of reduced diameter forming a seat for the front end of the casing 6, the casing being retained thereon by means of studs 11. The rear end of the casing 6 is similarly held in spaced concentric relation to the body section of the projectile by means of a plug member 12 on which the rear end of the casing is seated. Said plug has a central projection 13 seated loosely in a generally conforming recess 14 in a plug member 15 fixedly mounted in the front end of the tail section 4. The plug 12 is separated from the plug 15 by a space 10. As shown, this is accomplished by forming a shoulder on the projection 13 which bears on the adjacent surface of the plug 15. As best shown in Fig. 3, the capsule holder 7 is formed with passages 16 which communicate with the annular space 17 between the interior of the body section 2 and the exterior of the tubular casing 6; which space is arranged to conduct gas pressure to the space 10 to force the plug 15 and tail section 3' away from the body section 2.

A plurality of spools 18 of ribbon formed of reflecting material such as light metal or metallized plastic are lo cated within the casing 6 being enclosed in a longitudi nally split cylindrical sheath 19. Said sheath is freely slidable in the casing 6, abutting at its rear end and'seated on a reduced extension of the plug member 12, and at its forward end abutting against a thrust sleeve 21 which is also slidably mounted in the casing 6.

Discs 20 of suitable material such as fibre are interposed between the spools 18 to prevent them from matting or sticking together. These discs are preferably seated in circumferential grooves in the interior of the sheath as illustrated in order to maintain the spacing of the spools and protect them from compressive forces.

Split expansive spring rings 19a may, if desired, be mounted in grooves in the ends of the split sheath 19, or seated in grooves in the plug 12 and sleeve 21, in order to accelerate the separation of the halves of the sheath when it is ejected from the body of the projectile.

A spring 22 is interposed between the capsule holder 7 and thrust sleeve 21, being seated at its ends on reduced portions of said members, and is operative to eject the sheath 19 and the spools of chaff 18 therein when the tail section 3 has been detached from the body section of the projectile. Spring 22 is preferably attached at its ends in any suitable manner to the capsule holder 7 and the thrust sleeve 21, respectively.

The ends of the ribbons forming the spools 18 are passed by the discs 20, which may be notched for that purpose if necessary, brought together at the forward end of the package of spools and are tied and/or cemented to a cord 23. The forward end of said cord passes through a frangible diaphragm 24 fixedly mounted in any suitable manner in the rear end of the capsule holder 7. The end of cord 23 is knotted and/or embedded in a plastic globule as indicated at 25 to retain the end of the cord in the holder 7 as long as the diaphragm 24 is intact.

An explosive charge and timing mechanism therefor indicated generally by numeral 26 is mounted in the for ward end of the body section 2 in such position that the products of combustion of the explosive charge impinge on the holder 7 and pass through the passages 16 into the space 17 around the casing 6. Since the timing mechanism and explosive means form no part of the present invention further description thereof is deemed unnecessary. The function of this explosive charge is to blow off the tail section of the projectile and thus permit ejection of the chaff. It will be understood that the detonation of the charge will ordinarily be timed to occur at a suitable short time interval before the projectile reaches its highest elevation.

Means are provided for rupturing the diaphragm 24 to free the cord 23 and thus sever the attachment of the chaff to the projectile after a time interval sufficient to allow the ejected spools of chaff to unroll and stream. out back of the projectile. For this purpose a tubular capsule or cartridge 27 is fixedly mounted in theh-older 7 in any suitable manner in position for its contents to be ignited by the main explosive charge. The capsule 27 preferably contains at its front end a heat-sensitive initiating charge or cap 28, a body of slow-burning or fuzelike material 29 in contact therewith, and a gas-generating charge 30 adjacent to the diaphragm 24 for blowing it out after a predetermined time delay providedby the fuze 29.

In operation, when the main charge 26 is detonated, the blast traverses the passages 16 and space 17 and builds up pressure on the plug 15 in the end of the tail section 3, shearing off the frangible pins 5 and thus severing the tail section from the body section 2 of the projectile. This leaves the sheath 19 with the spools 18 of chaff contained therein free to slide out of the casing 6 under the pressure of the spring 22. The sections of the sheath 19 then separate and permit the spools of chaff to unwind and trail the projectile, their free ends being retained in the projectile by their attachment to the cord 23.

The explosion of the main charge 26 also sets off the initiating charge 28 in capsule 27, which ignites the slow burning mixture 29. After the elapse of sufficient time to allow the spools of chaff to unwind, the diaphragm 24 is ruptured by the charge 30, thus severing the connection of the chaff to the projectile while leaving the ribbons of chaff connected together at their forward ends. The chaff thus forms a coherent mass which 7 provides a satisfactory radar target.

In Fig. 4 of the drawing there is illustrated an embodiment of the invention in which the chaff is in the form of packages of short lengths of ribbons, rods or tubes of reflective material.

As there illustrated, the packages or bundles 41 are loosely wrapped in a strip of paper or the like 42, to facilitate handling, and are inserted in the split sheath 19 between spacing discs 20 mounted in said sheath in the same manner as in the first embodiment of the invention. I

The remaining elements are the same as in the first embodiment except that the cord 23, diaphragm 24 and capsule 27 are omitted, and the holder 47 is made solid halves of the sheath to fly apart. The loosely-held packages of chaff then disintegrate, and the contents'spread out to form the desired target. 1

Although certain structure has been shown'and described in detail it willbe understood that changes may be made in the design and arrangement of the parts without departing from the spirit of the invention.

We claim: 1. A meteorological projectile comprising a nose section, a hollow body section and a tail section closing the rear of the body section, frangible means for attaching the tail section to the body section, a plurality of packages of chaff in said body section, retained therein by the tail section, means including a compression spring for ejecting the chaff from the body section, when the tail section is removed, explosive means for blowing 0d the tail section of the projectile to permit ejection of the chaff by said spring means, a tubular casing enclosing the packages of chaff protecting the chaff from said explosive charge, but permitting passage of the products of explosion to force the tail section from the body section, a plug closing the rear end of said tubular casing, and a split cylindrical sheath surrounding said packages of chaff, slidable in said tubular casing and bearing against said plug; said ejecting means including a thrust member bearing against the forward end of said sheath, and actuated by said spring to slide the sheath and chaff out of the tubular casing when the tail section is severed from the body section of the projectile.

2. A meterological projectilecomprising a nose section, a hollow body section, and a tail section; frangible means for attaching the tail section to the body section, a plurality ofpackages of chaff in'the form of spools of ribbon in the body section retained therein by the tail section, means for uniting the ends of said chaff ribbons and connecting them to the body of the projectile, means including a compression spring for ejecting said chaff when the tail section is removed, explosive means for blowing off the tail section of the projectile to permit ejection of the spools of chaff by said spring means, and means operative a predetermined time after the ejection of said chaff to sever its connection to the body of the projectile; in which the means for connecting the united ends of the ribbons of chaff comprises a cord attached at its rear end to said ribbons, and at its forward end to a frangible diaphragm, and the means for severing the chaff from the projectile comprises an explosive charge for rupturing said diaphragm to free the cord, and means for igniting said charge a predetermined time after the exposion of said first-mentioned explosive means.

3. A device as set' forth in claim 1 including further means fixedly mounted in said sheath for separating said packages of chaff and protecting them from compressive forces.

4. A device as set forth in claim 3 in which said protecting means is in the form of discs fixedly mounted at spaced intervals in said sheath to separate the packages of chaff, but being released from the sheath when the sheath is ejected from'the tubular casing.

5. A device as set forth in claim 2 including further a holding member inserted in and attached to the forward end of the tubular casing to form a closure therefor and fixedly mounted in the body section to anchor said casing therein, said diaphragm being fixedly mounted in the holding member, a capsule in the holding member, an explosive charge in the capsule for rupturing the diaphragm, and means for igniting said exposive' charge a predetermined time after the blowing off of the tail section.

6. A device as set forth'in claim 5 in which'said igniting means comprises a slow-burning combustible mixture in said capsule and means for igniting said 'mixture by the explosive means for blowing off the tail of the pro jectile. V

7 References Cited in the file of this patent UNITED STATES PATENTS 1,709,644 Wiley Apr. 16, 1929 2,398,740 I Halvey Apr. 16, 1946 2,717,309 Campbell Sept. 6, 1955 FOREIGN PATENTS 1,133,213 France Nov. ,12, 6 

